Research & Scholarship

Current Research and Scholarly Interests

Clinical Trials

Rosuvastatin in Treating Patients With Stage I or Stage II Colon Cancer That Was Removed By SurgeryNot Recruiting

RATIONALE: Rosuvastatin may stop the growth of tumor cells by blocking some of the enzymes
needed for cell growth. Giving rosuvastatin after surgery may kill any tumor cells that
remain after surgery. It may also keep polyps from forming or colon cancer from coming back.
It is not yet known whether rosuvastatin is more effective than a placebo in treating colon
cancer that was removed by surgery.
PURPOSE: This randomized phase III trial is studying rosuvastatin to see how well it works
compared with placebo in treating patients with stage I or stage II colon cancer that was
removed by surgery.

Stanford is currently not accepting patients for this trial.For more information, please contact Shannon Meyer, (650) 724 - 1953.

Perfusion CT as a Predictor of Treatment Response in Patients With Rectal CancerRecruiting

A research study of rectal cancer perfusion (how blood flows to the rectum over time). We
hope to learn whether perfusion characteristics of rectal masses may be predictive of
response to treatment and whether rectal perfusion characteristics can be used to follow
response to treatment.

This study is about understanding the use of a genetic test (Myriad Genetics myRisk panel)
that analyzes 25 genes related to different hereditary cancer conditions. The
investigators hope to learn more about how this type of genetic test is used clinically.
The investigators also hope to understand more about the experience of individuals and
families who undergoing this test of genetic testing.

Abstract

Obesity and abdominal obesity are associated independently with morbidity and mortality. Physical activity attenuates these risks. We examined trends in obesity, abdominal obesity, physical activity, and caloric intake in US adults from 1988 to 2010.Univariate and multivariate analyses were performed using National Health and Nutrition Examination Survey data.Average body mass index (BMI) increased by 0.37% (95% confidence interval [CI], 0.30-0.44) per year in both women and men. Average waist circumference increased by 0.37% (95% CI, 0.30-0.43) and 0.27% (95% CI, 0.22-0.32) per year in women and men, respectively. The prevalence of obesity and abdominal obesity increased substantially, as did the prevalence of abdominal obesity among overweight adults. Younger women experienced the greatest increases. The proportion of adults who reported no leisure-time physical activity increased from 19.1% (95% CI, 17.3-21.0) to 51.7% (95% CI, 48.9-54.5) in women, and from 11.4% (95% CI, 10.0-12.8) to 43.5% (95% CI, 40.7-46.3) in men. Average daily caloric intake did not change significantly. BMI and waist circumference trends were associated with physical activity level but not caloric intake. The associated changes in adjusted BMIs were 8.3% (95% CI, 6.9-9.6) higher among women and 1.7% (95% CI, 0.68-2.8) higher among men with no leisure-time physical activity compared with those with an ideal level of leisure-time physical activity.Our analyses highlight important dimensions of the public health problem of obesity, including trends in younger women and in abdominal obesity, and lend support to the emphasis placed on physical activity by the Institute of Medicine.

Abstract

Heritable and environmental factors may contribute to differences in colorectal cancer (CRC) incidence across populations. We capitalized on the resources of the California Cancer Registry (CCR) and California's diverse Asian population to perform a cohort study exploring the relationships between CRC incidence, nativity, and neighborhood-level factors across Asian subgroups.We identified CRC cases in the CCR from 1990 to 2004 and calculated age-adjusted CRC incidence rates for non-Hispanic Whites and US-born vs. foreign-born Asian ethnic subgroups, stratified by neighborhood socioeconomic status (SES) and "ethnic enclave." Trends were studied with joinpoint analysis.CRC incidence was lowest among foreign-born South Asians (22.0/100,000; 95% confidence interval (CI): 19.7-24.5/100,000) and highest among foreign-born Japanese (74.6/100,000; 95% CI: 70.1-79.2/100,000). Women in all Asian subgroups except Japanese, and men in all Asian subgroups except Japanese and US-born Chinese, had lower CRC incidence than non-Hispanic Whites. Among Chinese men and Filipino women and men, CRC incidence was lower among foreign-born than US-born persons; the opposite was observed for Japanese women and men. Among non-Hispanic Whites, but not most Asian subgroups, CRC incidence decreased over time. CRC incidence was inversely associated with neighborhood SES among non-Hispanic Whites, and level of ethnic enclave among Asians.CRC incidence rates differ substantially across Asian subgroups in California. The significant associations between CRC incidence and nativity and residence in an ethnic enclave suggest a substantial effect of acquired environmental factors. The absence of declines in CRC incidence rates among most Asians during our study period may point to disparities in screening compared with Whites.

Abstract

Serrated colorectal lesions include hyperplastic polyps (HPs) and sessile serrated adenomas (SSAs). Optical biopsy could misclassify SSAs as unimportant if they resemble HPs.To explore the narrow-band imaging (NBI) features of SSAs. We hypothesized that SSAs resemble HPs under NBI.Retrospective analysis of data from our prospective study of NBI in routine practice.Single specialty group.Patients undergoing colonoscopy.Colonoscopy.Polyp histology prediction by community gastroenterologists. Features of SSAs versus HPs and adenomas by using the Narrow-Band Imaging International Colorectal Endoscopic (NICE) Classification.Among 2388 lesions, 141 were diagnosed on pathology as SSAs, 465 as HPs, and 1546 as adenomas. Each individual NICE feature of HPs was found in 38% to 42% of SSAs, 66% to 67% of HPs, and 15% to 20% of adenomas (P < .001 for each). Each individual NICE feature of adenomas was found in 57% to 62% of SSAs, 33% to 34% of HPs, and 80% to 84% of adenomas (P < .001 for each). Compared with HPs, SSAs were less likely (odds ratio [OR] 0.74; 95% confidence interval [CI], 0.69-0.79) and adenomas were even less likely (OR 0.62; 95% CI, 0.59-0.64) to have all 3 NICE features of HPs. SSAs >5 mm were more likely than smaller SSAs to have all 3 NICE features of adenomas. SSA location did not predict NBI features. Analyses restricted to high-confidence lesions showed similar results.The endoscopists were not NBI experts.Community gastroenterologists observed a profile of NICE features among SSAs that was intermediate to the profiles observed for HPs and adenomas. These results require confirmation by NBI experts.

Abstract

BACKGROUND: Screening of persons with newly diagnosed colorectal cancer (CRC) for Lynch syndrome can yield substantial benefits at acceptable costs, presuming sufficient uptake of genetic testing by first-degree relatives of Lynch syndrome probands. We performed a systematic review of the literature to determine the frequency of, and factors associated with, genetic testing of first-degree relatives of Lynch syndrome probands. METHODS: We searched 4 databases (CINAHL, PsycInfo, PUBMED, and SCOPUS) for articles published through May 2011 reporting uptake of genetic testing by relatives of Lynch syndrome probands. Two investigators independently screened articles to determine whether they met inclusion criteria; data were collected on populations, methodologies, and uptake of genetic testing. A narrative, qualitative systematic review was performed. RESULTS: We identified 1258 potentially relevant articles; 533 were fully reviewed and 8 were included in the final analysis. Of first-degree relatives of Lynch syndrome probands, 52% or less received genetic testing. For each proband, 4.6 or fewer relatives underwent genetic testing. Demographic factors (age <50 y, female sex, parenthood, level of education, employment, participation in medical studies), psychological factors (lack of depressive symptoms), and possibly family history (greater number of relatives with cancer) were associated with uptake of genetic testing. CONCLUSION: Based on a systematic review, genetic testing appears to be underutilized by first-degree relatives of patients with Lynch syndrome. The clinical benefit and economic feasibility of screening persons with CRC for Lynch syndrome depends on optimizing family-wide uptake of genetic testing. Future research and clinical efforts should focus on ways to overcome barriers to genetic testing.

Abstract

OBJECTIVES:Gastrointestinal (GI) emergencies may cause substantial morbidity. Our aims were to characterize the national clinical and economic burden of GI visits to emergency departments (EDs) in the United States.METHODS:We performed an observational cross-sectional study using the 2007 Nationwide Emergency Department Sample, the largest US all-payer ED database, to identify the leading causes for ED visits due to GI diseases and their associated charges, stratified by age and sex. Logistic regression was used to analyze predictors of hospitalization after an ED visit.RESULTS:Of the 122 million ED visits in 2007, 15 million (12%) had a primary GI diagnosis. The leading primary GI diagnoses were abdominal pain (4.7 million visits), nausea and vomiting (1.6 million visits), and functional disorders of the digestive system (0.7 million visits). The leading diagnoses differed by age group. The fraction of ED visits resulting in hospitalization was 21.6% for primary GI diagnoses vs. 14.7% for non-GI visits. Women had more ED visits with a primary GI diagnosis than men (58.5 (95% CI 56.0-60.9) vs. 41.6 (95% CI 39.8-43.3) per 1000 persons), but lower rates of subsequent hospitalization (20.0% (95% CI 19.4-20.7%) vs. 24.0% (95% CI 23.3-24.6%)). There were no differences in hospitalization rates between sexes after adjustment by age, primary GI diagnosis, and Charlson Comorbidity Score. The total charges for ED visits with a primary GI diagnosis in 2007 were $27.9 billion.CONCLUSIONS:GI illnesses account for substantial clinical and economic burdens on US emergency medical services.Am J Gastroenterol advance online publication, 16 July 2013; doi:10.1038/ajg.2013.199.

Abstract

BACKGROUND & AIMS: Colorectal cancer (CRC) screening guidelines recommend screening schedules for each single type of test except for concurrent sigmoidoscopy and fecal occult blood test (FOBT). We investigated the cost-effectiveness of a hybrid screening strategy that was based on a fecal immunological test (FIT) and colonoscopy. METHODS: We conducted a cost-effectiveness analysis by using the Archimedes Model to evaluate the effects of different CRC screening strategies on health outcomes and costs related to CRC in a population that represents members of Kaiser Permanente Northern California. The Archimedes Model is a large-scale simulation of human physiology, diseases, interventions, and health care systems. The CRC submodel in the Archimedes Model was derived from public databases, published epidemiologic studies, and clinical trials. RESULTS: A hybrid screening strategy led to substantial reductions in CRC incidence and mortality, gains in quality-adjusted life years (QALYs), and reductions in costs, comparable with those of the best single-test strategies. Screening by annual FIT of patients 50-65 years old and then a single colonoscopy when they were 66 years old (FIT/COLOx1) reduced CRC incidence by 72% and gained 110 QALYs for every 1000 people during a period of 30 years, compared with no screening. Compared with annual FIT, FIT/COLOx1 gained 1400 QALYs/100,000 persons at an incremental cost of $9700/QALY gained and required 55% fewer FITs. Compared with FIT/COLOx1, colonoscopy at 10-year intervals gained 500 QALYs/100,000 at an incremental cost of $35,100/QALY gained but required 37% more colonoscopies. Over the ranges of parameters examined, the cost-effectiveness of hybrid screening strategies was slightly more sensitive to the adherence rate with colonoscopy than the adherence rate with yearly FIT. Uncertainties associated with estimates of FIT performance within a program setting and sensitivities for flat and right-sided lesions are expected to have significant impacts on the cost-effectiveness results. CONCLUSIONS: In our simulation model, a strategy of annual or biennial FIT, beginning when patients are 50 years old, with a single colonoscopy when they are 66 years old, delivers clinical and economic outcomes similar to those of CRC screening by single-modality strategies, with a favorable impact on resources demand.

Abstract

Patient navigation (PN) is being used increasingly to help patients complete screening colonoscopy (SC) to prevent colorectal cancer. At their large, urban academic medical center with an open-access endoscopy system, the authors previously demonstrated that PN programs produced a colonoscopy completion rate of 78.5% in a cohort of 503 patients (predominantly African Americans and Latinos with public health insurance). Very little is known about the direct costs of implementing PN programs. The objective of the current study was to perform a detailed cost analysis of PN programs at the authors' institution from an institutional perspective.In 2 randomized controlled trials, average-risk patients who were referred for SC by primary care providers were recruited for PN between May 2008 and May 2010. Patients were randomized to 1 of 4 PN groups. The cost of PN and net income to the institution were determined in a cost analysis.Among 395 patients who completed colonoscopy, 53.4% underwent SC alone, 30.1% underwent colonoscopy with biopsy, and 16.5% underwent snare polypectomy. Accounting for the average contribution margins of each procedure type, the total revenue was $95,266.00. The total cost of PN was $14,027.30. Net income was $81,238.70. In a model sample of 1000 patients, net incomes for the institutional completion rate (approximately 80%), the historic PN program (approximately 65%), and the national average (approximately 50%) were compared. The current PN program generated additional net incomes of $35,035.50 and $44,956.00, respectively.PN among minority patients with mostly public health insurance generated additional income to the institution, mainly because of increased colonoscopy completion rates.

Abstract

Accurate optical analysis of colorectal polyps (optical biopsy) could prevent unnecessary polypectomies or allow a "resect and discard" strategy with surveillance intervals determined based on the results of the optical biopsy; this could be less expensive than histopathologic analysis of polyps. We prospectively evaluated real-time optical biopsy analysis of polyps with narrow band imaging (NBI) by community-based gastroenterologists.We first analyzed a computerized module to train gastroenterologists (N = 13) in optical biopsy skills using photographs of polyps. Then we evaluated a practice-based learning program for these gastroenterologists (n = 12) that included real-time optical analysis of polyps in vivo, comparison of optical biopsy predictions to histopathologic analysis, and ongoing feedback on performance.Twelve of 13 subjects identified adenomas with >90% accuracy at the end of the computer study, and 3 of 12 subjects did so with accuracy ?90% in the in vivo study. Learning curves showed considerable variation among batches of polyps. For diminutive rectosigmoid polyps assessed with high confidence at the end of the study, adenomas were identified with mean (95% confidence interval [CI]) accuracy, sensitivity, specificity, and negative predictive values of 81% (73%-89%), 85% (74%-96%), 78% (66%-92%), and 91% (86%-97%), respectively. The adjusted odds ratio for high confidence as a predictor of accuracy was 1.8 (95% CI, 1.3-2.5). The agreement between surveillance recommendations informed by high-confidence NBI analysis of diminutive polyps and results from histopathologic analysis of all polyps was 80% (95% CI, 77%-82%).In an evaluation of real-time optical biopsy analysis of polyps with NBI, only 25% of gastroenterologists assessed polyps with ?90% accuracy. The negative predictive value for identification of adenomas, but not the surveillance interval agreement, met the American Society for Gastrointestinal Endoscopy-recommended thresholds for optical biopsy. Better results in community practice must be achieved before NBI-based optical biopsy methods can be used routinely to evaluate polyps; ClinicalTrials.gov number, NCT01638091.

Abstract

Background: Screening reduces colorectal cancer (CRC) mortality, but many persons remain unscreened. Screening with a blood test could improve screening rates. We estimated the comparative effectiveness and cost-effectiveness of CRC screening with emerging biomarkers, illustrated by a methylated Septin 9 DNA plasma assay (mSEPT9), vs. established strategies. Methods: We conducted a cost-utility analysis using a validated decision analytic model comparing mSEPT9, fecal occult blood testing (FOBT), fecal immunochemical testing (FIT), sigmoidoscopy and colonoscopy, projecting benefits and costs over a lifetime. Results: In the base case, mSEPT9 decreased CRC incidence by 35-41% and CRC mortality by 53-61% at costs of $8,400-$11,500/quality-adjusted life year gained vs. no screening. All established screening strategies were more effective than mSEPT9. FIT was cost-saving, dominated mSEPT9, and was preferred among all the alternatives. Screening uptake and longitudinal adherence rates over time strongly influenced the comparisons between strategies. At the population level, mSEPT9 yielded incremental benefit at acceptable costs when it increased the fraction of the population screened more than it was substituted for other strategies. Conclusions: mSEPT9 appears to be effective and cost-effective compared with no screening. In order to be cost-effective compared with established strategies, mSEPT9 or blood-based biomarkers with similar test performance characteristics would need to achieve substantially higher uptake and adherence rates than the alternatives. It remains to be proven whether CRC screening with a blood test can improve screening uptake or long-term adherence compared with established strategies. Impact: Our study offer insights into the potential role of CRC screening with blood-based biomarkers.

Abstract

Fecal occult blood testing (FOBT) and sigmoidoscopy are proven to decrease colorectal cancer (CRC) incidence and mortality. Sigmoidoscopy's benefit is limited to the distal colon. Observational data are conflicting regarding the degree to which colonoscopy affords protection against proximal CRC. Our aim was to explore the comparative effectiveness and cost-effectiveness of colonoscopy vs. sigmoidoscopy and alternative CRC screening strategies in light of the latest published data.We performed a contemporary cost-utility analysis using a Markov model validated against data from randomized controlled trials of FOBT and sigmoidoscopy. Persons at average CRC risk within the general US population were modeled. Screening strategies included those recommended by the United States (US) Preventive Services Task Force, including colonoscopy every 10 years (COLO), flexible sigmoidoscopy every 5 years (FS), annual fecal occult blood testing, annual fecal immunochemical testing (FIT), and the combination FS/FIT. The main outcome measures were quality-adjusted life-years (QALYs) and costs.In the base case, FIT dominated other strategies. The advantage of FIT over FS and COLO was contingent on rates of uptake and adherence that are well above current US rates. Compared with FIT, FS and COLO both cost

Abstract

Current guidelines recommend offering genetic testing for Lynch syndrome to individuals whose tumors suggest this condition and to relatives of affected individuals. Little is known, however, regarding how patients view the prospect of such testing. In addition, data on preferences (utilities) for the potential outcomes of testing decisions for use in cost-effectiveness analyses are lacking.Time tradeoff utilities were elicited for 10 potential outcomes of Lynch syndrome testing decisions and 3 associated cancers from 70 participants, representing a range of knowledge about and experiences with Lynch syndrome.Highest mean utilities were assigned to scenarios in which only the assessor's sibling had Lynch-associated colorectal cancer (ranging from 0.669 ± 0.231 to 0.760 ± 0.220). Utilities assigned to scenarios in which the assessor had Lynch-associated colorectal cancer ranged from 0.605 ± 0.252 to 0.682 ± 0.246, whereas the lowest mean utilities were assigned to 2 of the general cancer states (0.601 ± 0.238 and 0.593 ± 0.272 for colorectal and ovarian cancer respectively). Only 43% of the sample assigned higher values to undergoing Lynch testing and receiving negative results versus forgoing Lynch testing, whereas 50% assigned higher values to undergoing rather than forgoing surgery to prevent a subsequent cancer.Genetic testing for Lynch syndrome, regardless of results, can have profound effects on quality of life; the utilities we collected can be used to incorporate these effects into cost-effectiveness analyses. Importantly, preferences for the potential outcomes of testing vary substantially, calling into question the extent to which patients would avail themselves of such testing if it were offered to them.

Abstract

Screening decreases colorectal cancer (CRC) incidence and mortality. Colonoscopy has become the most common CRC screening test in the United States, but the degree to which it protects against CRC of the proximal colon is unclear. We examined US trends in rates of resection for proximal vs distal CRC, which reflect CRC incidence, in the context of national CRC screening data, before and since Medicare's 2001 decision to pay for screening colonoscopy.We used the Nationwide Inpatient Sample, the largest US all-payer inpatient database, to estimate age-adjusted rates of resection for distal and proximal CRC, from 1993 to 2009, in adults. Temporal trends were analyzed using Joinpoint regression analysis.The rate of resection for distal CRC decreased from 38.7 per 100,000 persons (95% confidence interval [CI], 35.4-42.0) to 23.2 per 100,000 persons (95% CI, 20.9-25.5) from 1993 to 2009, with annual decreases of 1.2% (95% CI, 0.1%-2.3%) from 1993 to 1999, followed by larger annual decreases of 3.8% (95% CI, 3.3%-4.3%) from 1999 to 2009 (P < .001). In contrast, the rate of resection for proximal CRC decreased from 30.0 per 100,000 persons (95% CI, 27.4-32.5) to 22.7 per 100,000 persons (95% CI, 20.6-24.7) from 1993 to 2009, but significant annual decreases of 3.1% (95% CI, 2.3%-4.0%) occurred only after 2002 (P < .001). Rates of resection for CRC decreased for adults ages 50 years and older, but increased for younger adults.These findings support the hypothesis that population-level decreases in rates of resection for distal CRC are associated with screening, in general, and that implementation of screening colonoscopy, specifically, might be an important factor that contributes to population-level decreases in rates of resection for proximal CRC.

Abstract

Patients and relatives have varying preferences for genetic testing and interventions related to hereditary cancer syndromes. We examined how the impact of these services on quality of life (QoL) affects the cost-effectiveness of screening for Lynch syndrome among probands newly diagnosed with colorectal cancer and their relatives.We constructed a state-transition model comparing screening strategies (clinical criteria, prediction algorithms, tumor testing, and upfront germline testing) with no screening to identify Lynch syndrome. The model incorporated individuals' health state utilities after screening, germline testing, and risk-reducing surgeries, with utilities persisting for 12 months in the base case. Outcomes consisted of quality-adjusted life-years (QALYs), costs, and cost per QALY gained. Sensitivity analyses assessed how the duration and magnitude of changes in QoL influenced results.Multiple screening strategies yielded gains in QALYs at acceptable costs compared with no screening. The preferred strategy-immunohistochemistry of tumors followed by BRAF mutation testing (IHC/BRAF)-cost $59,700 per QALY gained in the base case. The duration and magnitude of decreases in QoL after decisions related to germline testing and surgeries were key determinants of the cost-effectiveness of screening. IHC/BRAF cost > $100,000 per QALY gained when decrements to QoL persisted for 21 months.Screening for Lynch syndrome in the population is likely to yield long-term gains in life expectancy that outweigh any short-term decreases in QoL, at acceptable costs. Counseling for individuals should aim to mitigate potential negative impact of genetic testing and risk-reducing interventions on QoL.

Abstract

Patients and relatives have varying preferences for genetic testing and interventions related to hereditary cancer syndromes. We examined how the impact of these services on quality of life (QoL) affects the cost-effectiveness of screening for Lynch syndrome among probands newly diagnosed with colorectal cancer and their relatives.We constructed a state-transition model comparing screening strategies (clinical criteria, prediction algorithms, tumor testing, and upfront germline testing) with no screening to identify Lynch syndrome. The model incorporated individuals' health state utilities after screening, germline testing, and risk-reducing surgeries, with utilities persisting for 12 months in the base case. Outcomes consisted of quality-adjusted lifeyears (QALYs), costs, and cost per QALY gained. Sensitivity analyses assessed how the duration and magnitude of changes in QoL influenced results.Multiple screening strategies yielded gains in QALYs at acceptable costs compared with no screening. The preferred strategy-immunohistochemistry of tumors followed by BRAF mutation testing (IHC/BRAF)-cost $59,700 per QALY gained in the base case. The duration and magnitude of decreases in QoL after decisions related to germline testing and surgeries were key determinants of the cost-effectiveness of screening. IHC/BRAF cost >$100,000 per QALY gained when decrements to QoL persisted for 21 months.Screening for Lynch syndrome in the population is likely to yield long-term gains in life expectancy that outweigh any short-term decreases in QoL, at acceptable costs. Counseling for individuals should aim to mitigate potential negative impact of genetic testing and risk-reducing interventions on QoL.

Abstract

Understanding racial/ethnic disparities in cancer screening by family history risk could identify critical opportunities for patient and provider interventions tailored to specific racial/ethnic groups. The authors evaluated whether breast cancer (BC) and colorectal cancer (CRC) disparities varied by family history risk using a large, multiethnic population-based survey.By using the 2005 California Health Interview Survey, BC and CRC screening were evaluated separately with weighted multivariate regression analyses, and stratified by family history risk. Screening was defined for BC as mammogram within the past 2 years for women aged 40 to 64 years; for CRC, screening was defined as annual fecal occult blood test, sigmoidoscopy within the past 5 years, or colonoscopy within the past 10 years for adults aged 50 to 64 years.The authors found no significant BC screening disparities by race/ethnicity or income in the family history risk groups. Racial/ethnic disparities were more evident in CRC screening, and the Latino-white gap widened among individuals with family history risk. Among adults with a family history for CRC, the magnitude of the Latino-white difference in CRC screening (odds ratio [OR], 0.28; 95% confidence interval [CI], 0.11-0.60) was more substantial than that for individuals with no family history (OR, 0.74; 95% CI, 0.59-0.92).Knowledge of their family history widened the Latino-white gap in CRC screening among adults. More aggressive interventions that enhance the communication between Latinos and their physicians about family history and cancer risk could reduce the substantial Latino-white screening disparity in Latinos most susceptible to CRC.

Abstract

The aim of this study was to establish key characteristics that patients, consumers, and health professionals value regarding genetic testing (GT) and personalized medicine using the example of GT for hereditary Lynch syndrome. We conducted a series of focus groups with individuals recruited from a clinic that follows those at high risk for hereditary cancer, individuals recruited from the community, physicians, and genetic counselors. Participants were presented with clinical scenarios about Lynch syndrome testing and asked to identify characteristics that they perceived as important in making decisions about GT. Forty-two participants (19 community members, 8 high-risk and cancer patients, 3 genetic counselors, and 8 physicians) participated. Among community members and patients, the most frequently discussed considerations were the personal impact of GT and family impact, respectively. Among physicians, the most frequently discussed topic was the characteristics of genomic services (e.g., test invasiveness); among genetic counselors, the most frequently discussed topic was evidence and recommendations. A variety of test characteristics were important in decision making about GT. High-risk patients, community members, and health care providers had different priorities. Health care professionals should be aware of differences between their own considerations about GT and those that are important to patients.

Abstract

Irritable bowel syndrome (IBS) imposes significant clinical and economic burdens. We aimed to characterize practice patterns for patients with IBS in a large health maintenance organization, analyzing point of diagnosis, testing, comorbidities, and treatment.Members of Kaiser Permanente Northern California who were diagnosed with IBS were matched to controls by age, sex, and period of enrollment. We compared rates of testing, comorbidities, and interventions.From 1995-2005, IBS was diagnosed in 141,295 patients (mean age, 46 years; standard deviation, 17 years; 74% female). Internists made 68% of diagnoses, gastroenterologists 13%, and others 19%. Lower endoscopy did not usually precede IBS diagnosis. Patients with IBS were more likely than controls to have blood, stool, endoscopic, and radiologic tests and to undergo abdominal or pelvic operations (odds ratios, 1.5-10.7; all P < .0001). Only 2.7% were tested for celiac disease, and only 1.8% were eventually diagnosed with inflammatory bowel disease. Chronic pain syndromes, anxiety, and depression were more common among IBS patients than among controls (odds ratios, 2.7-4.6; all P < .0001). Many patients with IBS were treated with anxiolytics (61%) and antidepressants (55%). Endoscopic and radiologic testing was most strongly associated with having IBS diagnosed by a gastroenterologist. Psychotropic medication use was most strongly associated with female sex.In a large, managed care cohort, most diagnoses of IBS were made by generalists, often without endoscopic evaluation. Patients with IBS had consistently higher rates of testing, chronic pain syndromes, psychiatric comorbidity, and operations than controls. Most patients with IBS were treated with psychiatric medications.

Abstract

Scientific advances have improved our ability to target cancer interventions to individuals who will benefit most and spare the risks and costs to those who will derive little benefit or even be harmed. Several approaches are currently used for targeting interventions for cancer risk reduction, screening, and treatment, including risk prediction algorithms for identifying high-risk subgroups and diagnostic tests for tumor markers and germline genetic mutations. Economic evaluation can inform decisions about the use of targeted interventions, which may be more costly than traditional strategies. However, assessing the impact of a targeted intervention on costs and health outcomes requires explicit consideration of the method of targeting. In this study, we describe the importance of this principle by reviewing published cost-effectiveness analyses of targeted interventions in breast cancer. Few studies we identified explicitly evaluated the relationships among the method of targeting, the accuracy of the targeting test, and outcomes of the targeted intervention. Those that did found that characteristics of targeting tests had a substantial impact on outcomes. We posit that the method of targeting and the outcomes of a targeted intervention are inextricably linked and recommend that cost-effectiveness analyses of targeted interventions explicitly consider costs and outcomes of the method of targeting.

Abstract

Testing has been advocated for all persons with newly diagnosed colorectal cancer to identify families with the Lynch syndrome, an autosomal dominant cancer-predisposition syndrome that is a paradigm for personalized medicine.To estimate the effectiveness and cost-effectiveness of strategies to identify the Lynch syndrome, with attention to sex, age at screening, and differential effects for probands and relatives.Markov model that incorporated risk for colorectal, endometrial, and ovarian cancers.Published literature.All persons with newly diagnosed colorectal cancer and their relatives.Lifetime.Third-party payer.Strategies based on clinical criteria, prediction algorithms, tumor testing, or up-front germline mutation testing, followed by tailored screening and risk-reducing surgery.Life-years, cancer cases and deaths, costs, and incremental cost-effectiveness ratios.The benefit of all strategies accrued primarily to relatives with a mutation associated with the Lynch syndrome, particularly women, whose life expectancy could increase by approximately 4 years with hysterectomy and salpingo-oophorectomy and adherence to colorectal cancer screening recommendations. At current rates of germline testing, screening, and prophylactic surgery, the strategies reduced deaths from colorectal cancer by 7% to 42% and deaths from endometrial and ovarian cancer by 1% to 6%. Among tumor-testing strategies, immunohistochemistry followed by BRAF mutation testing was preferred, with an incremental cost-effectiveness ratio of $36,200 per life-year gained.The number of relatives tested per proband was a critical determinant of both effectiveness and cost-effectiveness, with testing of 3 to 4 relatives required for most strategies to meet a threshold of $50,000 per life-year gained. Immunohistochemistry followed by BRAF mutation testing was preferred in 59% of iterations in probabilistic sensitivity analysis at a threshold of $100,000 per life-year gained. Screening for the Lynch syndrome with immunohistochemistry followed by BRAF mutation testing only up to age 70 years cost $44,000 per incremental life-year gained compared with screening only up to age 60 years, and screening without an upper age limit cost $88,700 per incremental life-year gained compared with screening only up to age 70 years.Other types of cancer, uncertain family pedigrees, and genetic variants of unknown significance were not considered.Widespread colorectal tumor testing to identify families with the Lynch syndrome could yield substantial benefits at acceptable costs, particularly for women with a mutation associated with the Lynch syndrome who begin regular screening and have risk-reducing surgery. The cost-effectiveness of such testing depends on the participation rate among relatives at risk for the Lynch syndrome.National Institutes of Health.

Abstract

The PIVI (Preservation and Incorporation of Valuable endoscopic Innovations) initiative is an ASGE program whose objectives are to identify important clinical questions related to endoscopy and to establish a priori diagnostic and/or therapeutic thresholds for endoscopic technologies designed to resolve these clinical questions. Additionally, PIVIs may also outline the data and or the research study design required for proving an established threshold is met. Once endoscopic technologies meet an established PIVI threshold, those technologies are appropriate to incorporate into clinical practice presuming the appropriate training in that endoscopic technology has been achieved. The ASGE encourages and supports the appropriate use of technologies that meet its established PIVI thresholds. The PIVI initiative was developed primarily to direct endoscopic technology development toward resolving important clinical issues in endoscopy. The PIVI initiative is also designed to minimize the possibility that potentially valuable innovations are prematurely abandoned due to lack of utilization and to avoid widespread use of an endoscopic technology before clinical studies documenting their effectiveness have been performed. The following document, or PIVI, is one of a series of statements defining the diagnostic or therapeutic threshold that must be met for a technique or device to become considered appropriate for incorporation into clinical practice. It is also meant to serve as a guide for researchers or those seeking to develop technologies that are designed to improve digestive health outcomes. An ad hoc committee under the auspices of the existing ASGE Technology and Standards of Practice Committees Chairs develops PIVIs. An expert in the subject area chairs the PIVI, with additional committee members chosen for their individual expertise. In preparing this document, evidence-based methodology was employed, using a MEDLINE and PubMed literature search to identify pertinent clinical studies on the topic. PIVIs are ultimately submitted to the ASGE Governing Board for approval, as is done for all Technology and Standards of Practice documents. This document is provided solely for educational and informational purposes and to support incorporating these endoscopic technologies into clinical practice. It should not be construed as establishing a legal standard of care.

Abstract

The effectiveness of screening and treatment of recurrent hepatocellular carcinoma (HCC) after liver transplantation (LT) remains undefined. Our aim was to evaluate the potential cost-effectiveness of screening for recurrent HCC after LT. We constructed a Markov model of the natural history after LT for HCC. We superimposed screening with computed tomography, alpha-fetoprotein, and chest X-ray every six months for 1-5 yr after LT, with resection for treatable recurrence. Screening only those whose explant pathology exceeded Milan Criteria (MC) for two yr cost $ 138,000/life-yr gained, and the incremental cost of screening all patients was $ 340,000/life-yr gained. Screening for longer than two yr incurred progressively higher incremental costs/life-yr gained. The most critical variable in sensitivity analyses was the survival benefit of finding a resectable recurrence. With the most favorable assumptions for a two-yr screening duration, screening those whose explant pathology exceeded MC cost $ 91,000/life-yr gained. In conclusion, screening for HCC recurrence after LT would probably yield most of its benefit in the first two yr, but at a relatively high cost/life-yr gained. Screening for two yr in only those whose explant pathology exceeds MC may be relatively cost-effective depending on the survival benefit of resection.

Abstract

The European Community has made a commitment to colorectal cancer (CRC) screening, but regional considerations may affect the design of national screening programs. We developed a decision analytic model tailored to a pilot screening program for high-risk persons in Spain with the aim of informing public policy decisions.We constructed a decision analytic Markov model based on our validated model of CRC screening that reflected CRC epidemiology and costs in persons with first-degree relatives with CRC in Aragón, Spain, and superimposed colonoscopy every 5 or 10 years from ages 40 to 80 years. The pilot program's preliminary clinical results and our modeling results were presented to regional health authorities.In the model, without screening, 88 CRC cases occurred per 1,000 persons from age 40 to 85 years. In the base case, screening reduced this by 72% to 77% and gained 0.12 discounted life years per person. Screening every 10 years was cost saving, and screening every 5 years versus every 10 years cost 7,250 euros per life year gained. Based on these savings, 36 to 39 euros per person per year could go toward operating costs while maintaining a neutral budget. If screening costs doubled, screening remained highly cost-effective but no longer cost saving. These results contributed to the health authorities' decision to expand the pilot program to the entire region in 2009.Colonoscopic screening of first-degree relatives of persons with CRC may be cost saving in public systems like that of Spain. Decision analytic modeling tailored to regional considerations can inform public policy decisions.Tailored decision analytic modeling can inform regional policy decisions on cancer screening.

Abstract

To determine the rate and yield of repeat esophagogastroduodenoscopy (EGD) for dyspepsia in clinical practice, whether second opinions drive its use, and whether it is performed at the expense of colorectal cancer screening.We performed a retrospective cohort study of all patients who underwent repeat EGD for dyspepsia from 1996 to 2006 at the University of California, San Francisco endoscopy service.Of 24,780 EGDs, 5460 (22%) were performed for dyspepsia in 4873 patients. Of these, 451 patients (9.3%) underwent repeat EGD for dyspepsia at a median 1.7 (interquartile range, 0.8-3.1) years after initial EGD. Significant findings possibly related to dyspepsia were more likely at initial (29%) vs repeat EGD (18%) [odds ratio (OR), 1.45; 95% confidence interval (CI): 1.20-1.75, P < 0.0001], and at repeat EGD if the initial EGD had reported such findings (26%) than if it had not (14%) (OR, 1.32; 95% CI: 1.08-1.62, P = 0.0015). The same endoscopist performed the repeat and initial EGD in 77% of cases. Of patients aged 50 years or older, 286/311 (92%) underwent lower endoscopy.Repeat EGD for dyspepsia occurred at a low but substantial rate, with lower yield than initial EGD. Optimizing endoscopy use remains a public health priority.

Abstract

Data on the benefit of selective serotonin reuptake inhibitors (SSRIs) in irritable bowel syndrome (IBS) are conflicting. The longitudinal relationship between clinical symptoms and sensitivity to barostat-mediated rectal distension in IBS remains unclear. We assessed the benefit of citalopram and explored the relationships between symptoms, quality of life (QOL), and rectal sensitivity to barostat distension in non-depressed IBS patients.Patients from primary, secondary, and tertiary care settings were randomly assigned to receive citalopram (20 mg/day for 4 weeks, then 40 mg/day for 4 weeks) or placebo in a study with double-masking and concealed allocation. Symptoms were assessed weekly, and IBS-QOL and rectal sensation by barostat were assessed at the beginning and end of the study.Patients receiving citalopram did not achieve a higher rate of adequate relief of IBS symptoms than patients receiving placebo (12/27 [44%] vs 15/27 [56%]; P = .59), regardless of IBS subtype. The odds ratio for weekly response with citalopram vs placebo was 0.80 (95% confidence interval, 0.61-1.04). Improvements in specific symptom and IBS-QOL scores were not superior for citalopram. Changes in IBS-QOL score and pressure eliciting pain showed a modest correlation (r = 0.33; 95% confidence interval, 0.03-0.57), but changes in symptoms and IBS-QOL scores or rectal sensitivity were not correlated substantially.Citalopram was not superior to placebo in treating non-depressed IBS patients. Changes in symptoms were not substantially correlated with changes in rectal sensation assessed by barostat. Any benefit of citalopram in non-depressed IBS patients is likely to be modest at best.

Abstract

Esophageal verrucous carcinoma is a rare variant of esophageal squamous cell carcinoma. We report a case of esophageal verrucous carcinoma associated with human papilloma virus (HPV) type 51. The patient had long-standing dysphagia and odynophagia, and white esophageal plaques showing hyperkeratosis on biopsy. At repeat endoscopy, the esophagus was covered with verrucous white plaques and areas of nodular mucosa with white fronds, with a distal 10-cm smooth mass protruding into the lumen. Biopsies demonstrated an atypical squamoproliferative lesion but no frank malignancy. HPV type 51 DNA was detected in endoscopic biopsy specimens by polymerase chain reaction. Because the size of the lesion favored an underlying verrucous carcinoma, our patient underwent minimally invasive esophagectomy with gastric pull-up and cervical anastomosis. The pathologic diagnosis was a well-differentiated esophageal verrucous carcinoma. One year after esophagectomy, the patient feels well and is free of disease. Although HPV DNA was not detected in the cancer tissue obtained at surgery, our case suggests an association between HPV type 51 and esophageal verrucous carcinoma. The clinical evolution in this case highlights the importance of endoscopic surveillance in patients with exuberant esophageal hyperkeratosis, and of definitive surgical resection when malignancy is suspected even if frank malignancy is not demonstrated on superficial biopsies.

Abstract

Colorectal cancer (CRC) is a feared complication of chronic ulcerative colitis (UC). Annual endoscopic surveillance is recommended for the detection of early neoplasia. 5-Aminosalicylates (5-ASAs) may prevent some UC-associated CRC. Therefore, in patients prescribed 5-ASAs for maintenance of remission, annual surveillance might be overly burdensome and inefficient. We aimed to determine the ideal frequency of surveillance in patients with UC maintained on 5-ASAs.We performed systematic reviews of the literature, and created a Markov computer model simulating a cohort of 35-year-old men with chronic UC, followed until the age of 90 years. Twenty-two strategies were modeled: natural history (no 5-ASA or surveillance), surveillance without 5-ASA at intervals of 1-10 years, 5-ASA plus surveillance every 1-10 years, and 5-ASA alone. The primary outcome was the ideal interval of surveillance in the setting of 5-ASA maintenance, assuming a third-party payer was willing to pay $100,000 for each quality-adjusted life-year (QALY) gained.In the natural history strategy, the CRC incidence was 30%. Without 5-ASA, annual surveillance was the ideal strategy, preventing 89% of CRC and costing $69,100 per QALY gained compared with surveillance every 2 years. 5-ASA alone prevented 49% of CRC. In the setting of 5-ASA, surveillance every 3 years was ideal, preventing 87% of CRC. 5-ASA with surveillance every 2 years cost an additional $147,500 per QALY gained, and 5-ASA with annual surveillance cost nearly $1 million additional per QALY gained compared with every 2 years. In Monte Carlo simulations, surveillance every 2 years or less often was ideal in 95% of simulations.If 5-ASA is efficacious chemoprevention for UC-associated CRC, endoscopic surveillance might be safely performed every 2 years or less often. Such practice could decrease burdens to patients and on endoscopic resources with a minimal decrease in quality-adjusted length of life, because 5-ASA with annual surveillance may cost nearly $1 million per additional QALY gained.

Abstract

Pharmacogenomics aims to use molecular genetic markers to predict treatment outcome. Indeed, within the past decade there has been a rapid emergence of pharmacogenetic tests to aid clinicians in predicting efficacy or toxicity for some drugs. Despite this major advance in therapeutic drug management, there remain challenges to the appropriate use of pharmacogenetic tests. We discuss UGT1A1 pharmacogenetic testing to illustrate the knowledge gaps impeding widespread use of pharmacogenetic tests in the clinical setting.

Abstract

The aim of this study was to examine the potential cost-effectiveness of calcium chemoprevention post-polypectomy as a substitute or adjunct for surveillance.We constructed a Markov model of post-polypectomy adenoma recurrence and colorectal cancer (CRC) development, calibrated to data from prospective chemoprevention trials of fiber, calcium, antioxidants, and aspirin. We modeled four scenarios for 50-year-old patients immediately after polypectomy: (i) natural history with no further intervention; (ii) elemental calcium 1,200 mg/day from age 50-80; (iii) surveillance colonoscopy from age 50-80 every 5 years, or 3 years for large adenoma; (iv) calcium + surveillance. Patients were followed up until age 100 or death.Calcium was cost-effective compared to natural history ($49,900/life-year gained). However, surveillance was significantly more effective than calcium (18.729 versus 18.654 life-years/patient; 76 percent versus 14 percent reduction in CRC incidence) at an incremental cost of $15,900/life-year gained. Calcium + surveillance yielded a very small benefit (0.0003 incremental life-years/patient) compared with surveillance alone, at a substantial incremental cost of $3,090,000/life-year gained.Post-polypectomy calcium chemoprevention is unlikely to be a reasonable substitute for surveillance. It may be cost-effective in patients unwilling or unable to undergo surveillance.

Abstract

Oral 5-aminosalicylic acid (5-ASA, mesalamine) is effective in inducing and maintaining remission in ulcerative colitis (UC). The relative benefits and costs of maintenance 5-ASA therapy are uncertain. Our aims were to evaluate this strategy's potential cost-effectiveness.We constructed a Markov model to compare two strategies over 2 yr: (a) no maintenance 5-ASA, with 5-ASA 4.8 g/day given for flares, (b) maintenance 5-ASA 2.4 g/day, escalated and maintained at 4.8 g/day after the first flare. In both arms, the failure to induce remission led to other treatments, as needed: prednisone, parenteral corticosteroids, cyclosporine, 6-mercaptopurine, infliximab, and colectomy.Without maintenance 5-ASA, the mean flares per person were 1.92, and the mean cost per person was $3,402. With maintenance 5-ASA providing a relative risk of flare of 0.7 at 5-ASA cost of $198/month, flares per person decreased to 1.38 at a cost of $8,810/flare prevented. Maintenance 5-ASA increased discounted quality-adjusted life-years per person (QALYs per person) from 1.75 to 1.77 at a discounted cost of $224,000/QALY gained. The results were most sensitive to the flare risk reduction and cost of 5-ASA, the utilities of being in remission without or with 5-ASA, and the colectomy rates. At $15/month (the cost of sulfasalazine), maintenance 5-ASA cost $640/flare prevented and $16,300/QALY gained.Maintenance 5-ASA therapy decreases UC flares, but its cost may be substantial, depending on society's willingness to pay. If sulfasalazine can be tolerated and yields comparable benefits, sulfasalazine maintenance therapy is likely to be cost-effective. The cost per QALY gained by 5-ASA maintenance is highly dependent on the quality of life while taking versus not taking maintenance 5-ASA, highlighting the importance of patients' preferences.

Abstract

Although colonoscopy is used in the diagnostic evaluation of patients with diverticular hemorrhage, data on colonoscopic treatment outcomes are limited. We reviewed records of inpatients undergoing colonoscopy to identify patients that were colonoscopically diagnosed and treated for acute diverticular hemorrhage. Eleven patients with acute diverticular hemorrhage had active bleeding (n = 7) or non-bleeding visible vessel (n = 4) at colonoscopy. Endoclip treatment (preceded by epinephrine injection in 64%) achieved hemostasis in all patients without procedural complications. Patients were discharged within three days without evidence of early rebleeding. During a median follow-up of 15 months, late recurrent bleeding occurred in two patients (18.2%). Colonoscopic treatment of patients with acute diverticular hemorrhage using endoclips appears to be effective and safe, with high rates of immediate and long-term success. Colonoscopy should be considered in patients with suspected acute diverticular hemorrhage, as it may enable definitive therapy without the need for more invasive treatment.

Abstract

A major health priority is to increase colorectal cancer screening, and colonoscopy has become an increasingly important method of screening. The Medicare program began coverage for colonoscopy for average risk individuals in 2001.We sought to examine whether overall colorectal cancer screening increased over time and whether these increases were a result of increased utilization of all methods or a result of greater use of colonoscopy but reduced use of other methods, whether the enactment of Medicare coverage was associated with an increase in colonoscopy among Medicare enrollees, and whether these trends equally affected subpopulations.We used nationally representative data from the 2000 and 2003 National Health Interview Surveys and analyzed data using used chi, difference-in-differences tests, and logistic regression analyses to examine whether screening rates differed between 2000 and 2003.The percentage of individuals being screened for colorectal cancer using any method increased modestly from 2000 to 2003 (3%), with increases a result of increased use of colonoscopy and a reduction in the use of other methods. Increases in colonoscopy use were significant among all populations except the insured, non-Medicare population with low incomes. Among Medicare enrollees with high/middle incomes, colonoscopy use increased 14% from 2000 to 2003 compared with an increase of only 7% among low-income groups, which was a significant difference (P < 0.01). Similarly, among insured, non-Medicare enrollees with high/middle incomes, colonoscopy use increased 11% from 2000 to 2003 compared with an increase of only 4% among low-income groups, which also was a significant difference (P < 0.01).Colorectal cancer screening utilization increased modestly from 2000 to 2003, with the increases that primarily were the result of increased colonoscopy use. Increases in colonoscopy use, however, were primarily among high/middle income groups. Although Medicare coverage may have indirectly facilitated the increase in colonoscopy, we could not determine that coverage directly increased screening rates. Screening rates remain modest and lower income individuals continue to be screened less. Topics for future research include approaches to facilitating screening among low-income individuals and evaluating the impact of policy coverage decisions.

Abstract

The brain representation of visceral stimulation bears important similarities to that of somatic stimulation. However, the role of the primary (S1) and secondary (S2) somatosensory cortices in mediating gastric sensation is uncertain.Eighteen healthy, right-handed volunteers (age 32 years+/-6.5 years; 14 men) underwent dynamic assessment of the relationship between sensation and fundic barostat distending pressure and volume, and then brain functional magnetic resonance imaging (fMRI) during noxious fundic distension. Cytoarchitectonic probability maps were used to examine in detail the null hypothesis that fundic distension did not produce significant activation of S1 or S2.Distending volume explained 74% of the variance in gastric sensation, compared to 64% with distending pressure. Incorporating distending volume into the regressor function for our fMRI analyses, we found that noxious fundic distension activated a widespread network of brain regions, including the pontine brainstem, thalami, cerebellum, insular cortex bilaterally, anterior and posterior cingulate cortex, right frontal lobe, and inferior parietal lobules. In detailed analyses, we found no evidence of activation of S1, but did find activation in one region of S2.Our findings suggest that an extensive, predominantly fronto-limbic network of brain regions, including the insular cortex, mediates perception of noxious gastric fundic distension in healthy humans, without significant participation by the primary somatosensory cortex. This and other recent studies lay the groundwork for investigations comparing brain processing of visceral stimuli between healthy volunteers and patients with functional dyspepsia.

Abstract

Despite widespread recommendations for colorectal cancer screening, the U.S. screening rate is low. The objectives of this study were to describe the rates and predictors of colorectal cancer screening use by examining groups in two categories--1) those who have ever been screened and 2) those with up-to-date screening--and to assess whether trends and predictors change over time.We analyzed data from the 2000 and 2003 National Health Interview Surveys about the use of fecal occult blood tests, sigmoidoscopies, and colonoscopies for adults aged 50 years and older and without a history of colorectal cancer (N = 11,574 in 2000 and N = 11,779 in 2003).Rates in the 2000 study population of those who have ever been screened for colorectal cancer (53%) had increased in the 2003 study population (55%) as had the rates in the 2003 study population of those with up-to-date colorectal screening (53%) compared with the rates in the 2000 study population (38%). Among those who were ever screened, 76% were up-to-date with screening in 2003, compared with 68% in 2000. There was increased use of colonoscopies but decreased use of fecal occult blood tests and sigmoidoscopies. Individuals were more likely to be up-to-date with screening if they had higher income, higher education, insurance coverage, a usual source of care, and a dental visit in the last year than if these predictors were not evident. Since 2000, these predictors of colorectal cancer screening use have remained stable.Although there has been relatively limited success in increasing overall screening, it is encouraging that most people in the group of those who have ever been screened are up-to-date with colorectal cancer screening. Predictors for colorectal screening were stable over time despite changes in screening policies and rates. Further research is needed to uncover barriers to colorectal cancer screening.

Abstract

Colorectal cancer (CRC) incidence rises with age, and most CRC arises from adenomatous polyps. It was therefore hypothesized that increased use of CRC screening and polypectomy in younger persons might yield CRC-related savings later in life for payers such as Medicare.Using a decision analytic Markov model, the impact of increased CRC screening uptake on healthcare payers for younger Americans versus payers for older Americans, such as Medicare, was projected.As screening uptake increased, CRC incidence and mortality decreased, and annual costs related to CRC care and testing increased for younger persons, but decreased for older persons. Compared with current screening uptake of 40%, screening 75% of the U.S. population aged 50 to 80 increased annual costs related to CRC care and testing from 3.6 billion US dollars to 5.0 billion US dollars for 50- to 64-year-olds, but decreased annual costs from 5.9 billion US dollars to 5.6 billion US dollars for those aged 65 years and older. Sensitivity analyses suggest that future costs for other diseases could offset CRC care savings in older Americans that are attributable to screening. However, even without net cost savings for any age group, screening remained relatively cost-effective.Investments in screening and polypectomy in younger persons may decrease CRC-related costs, including screening and surveillance, for healthcare payers for older Americans, including Medicare. While these savings could potentially be offset by future health costs for other diseases, screening would still be cost-effective. Widespread CRC screening beginning at age 50 must remain a national priority.

Abstract

Colorectal cancer (CRC) screening is effective and cost-effective, but the potential national impact of widespread screening is uncertain. It is controversial whether screening colonoscopy can be offered widely and how emerging tests may impact health services demand. Our aim was to produce integrated, comprehensive estimates of the impact of widespread screening on national clinical and economic outcomes and health services demand.We used a Markov model and census data to estimate the national consequences of screening 75% of the US population with conventional and emerging strategies.Screening decreased CRC incidence by 17%-54% to as few as 66,000 cases per year and CRC mortality by 28%-60% to as few as 23,000 deaths per year. With no screening, total annual national CRC-related expenditures were 8.4 US billion dollars. With screening, expenditures for CRC care decreased by 1.5-4.4 US billion dollars but total expenditures increased to 9.2-15.4 US billion dollars. Screening colonoscopy every 10 years required 8.1 million colonoscopies per year including surveillance, with other strategies requiring 17%-58% as many colonoscopies. With improved screening uptake, total colonoscopy demand increased in general, even assuming substantial use of virtual colonoscopy.Despite savings in CRC care, widespread screening is unlikely to be cost saving and may increase national expenditures by 0.8-2.8 US billion dollars per year with conventional tests. The current national endoscopic capacity, as recently estimated, may be adequate to support widespread use of screening colonoscopy in the steady state. The impact of emerging tests on colonoscopy demand will depend on the extent to which they replace screening colonoscopy or increase screening uptake in the population.

Abstract

Paraneoplastic symptoms caused by abnormal gastrointestinal motility may be the initial manifestation of small cell lung cancer (SCLC). We report a case of a 63-year-old woman who presented with progressive constipation culminating in obstipation, and associated symptoms of more widespread dysmotility. A paraneoplastic syndrome was suspected. The only abnormality on chest computed tomography was a minimally enlarged paratracheal lymph node. Positron emission tomography demonstrated increased activity in the lymph node. The antinuclear neuronal antibody titer was elevated. Bronchoscopy with transtracheal biopsy confirmed the diagnosis of SCLC. One year after diagnosis, the patient had progressive symptoms of intestinal obstruction, and ultimately feculent vomiting. On abdominal radiography, colonic sitz markers ingested a year earlier were in virtually the same positions as after ingestion. Palliative colectomy with ileostomy was performed. The myenteric plexus in the terminal ileum and colon showed infiltration by a mixture of B-cell and T-cell lymphocytes and plasma cells, and no gross neuronal abnormalities. We review the clinical and pathologic features, clinical course, and management of paraneoplastic pseudoobstruction.

Abstract

HCV-related cirrhosis is a leading risk factor for hepatocellular carcinoma (HCC). Surveillance might detect HCC at a treatable stage. We estimated the clinical and economic consequences of a common HCC surveillance strategy in patients with HCV-related cirrhosis in the context of alternative HCC treatment strategies.With a Markov model, we examined surveillance with serum alpha-fetoprotein and ultrasound every 6 months in patients with compensated HCV-related cirrhosis from age 45-70 years or death, and HCC treatment with resection, cadaveric liver transplantation (CLT), or living donor liver transplantation (LDLT).Compared to natural history in the base case, surveillance with resection, listing for CLT, or LDLT increased life expectancy by 0.49, 2.58, and 3.81 quality-adjusted life-years (QALYs), respectively, all at costs less than 51,000 US dollars/QALY gained. The consequences of surveillance were most sensitive to the outcomes and costs of HCC treatments but not surveillance test performance characteristics or cost. Prioritizing CLT for patients with HCC over those with decompensated cirrhosis resulted in greater overall life expectancy with minimal increase in cost.Surveillance for HCC in patients with compensated HCV-related cirrhosis might gain QALYs at acceptable costs. The impact of surveillance depends most on the outcomes and costs of HCC treatments, rather than surveillance test characteristics. By increasing organ availability for timely definitive treatment, LDLT might achieve the greatest gain in life expectancy at acceptable costs. Prioritizing CLT for HCC might increase the population-wide benefits of CLT.

Abstract

When optimized, virtual colonoscopy may be highly sensitive for colorectal neoplasia. We evaluated the effectiveness and cost-effectiveness of virtual colonoscopy screening (VC) vs. colonoscopy screening (COLO) and the potential impact at the national level.Using a Markov model, we estimated the clinical and economic consequences of VC and COLO from ages 50 to 80 years. Using census data, we made projections to the national level.In the best case considered (95%, 94%, and 87% sensitivity for colorectal cancer [CRC], polyps > or =10 mm, and polyps <10 mm), VC was nearly as effective as COLO. However, if test costs were equal, total cost per person was 15% greater for VC than COLO, making COLO dominant. When test cost for VC was < or =60% of test cost for COLO, the small benefit of COLO vs. VC cost >200,000 US dollars/incremental life-year. The greater the likelihood of being referred for colonoscopy after VC, the greater the advantage of COLO. With 75% screening adherence in the United States, VC and COLO could decrease CRC incidence by 46%-54%, with COLO requiring 6.9 million colonoscopies/yr, and VC, 3.2 million colonoscopies/yr, plus 5.4 million virtual colonoscopies/yr with VC.Even if screening test sensitivities were similar, COLO is likely to be preferred over VC unless virtual colonoscopy costs significantly less than colonoscopy. VC may be most appropriate in persons unlikely to need colonoscopy, such as those at low CRC risk. If VC were substituted for COLO, the demand on resources would shift from endoscopic to radiologic services, but would not diminish.

Abstract

Patients diagnosed with irritable bowel syndrome may have coeliac disease.To evaluate the cost-effectiveness of coeliac disease testing in suspected irritable bowel syndrome.We used decision analysis to estimate the number of coeliac disease cases detected, quality-adjusted life-years gained, and costs resulting from testing suspected irritable bowel syndrome patients for tissue transglutaminase antibody or an antibody panel (tissue transglutaminase, gliadin, total immunoglobulin A). Positive tests prompted endoscopic biopsy. A gluten-free diet improved quality of life in coeliac disease.Assuming a coeliac disease prevalence of 3%, tissue transglutaminase detected 28 and the panel detected 29 of 30 coeliac disease cases among 1000 suspected irritable bowel syndrome patients. The cost/case detected was $4600 with tissue transglutaminase and $8800 with the panel. The cost/quality-adjusted life-year gained with tissue transglutaminase was $7400, and the incremental cost/quality-adjusted life-year gained for the panel vs. tissue transglutaminase was $287 000. Tissue transglutaminase cost under $100 000/quality-adjusted life-year gained at a coeliac disease prevalence >/=1.1%, assuming a modest utility gain of 0.005 with coeliac disease diagnosis.Testing for coeliac disease in patients with suspected irritable bowel syndrome is likely to be cost-effective even at a relatively low coeliac disease prevalence and with small improvements in quality of life with a gluten-free diet.

Abstract

Fecal DNA testing is an emerging tool to detect colorectal cancer (CRC). Our aims were to estimate the clinical and economic consequences of fecal DNA testing vs. conventional CRC screening.Using a Markov model, we estimated CRC incidence, CRC mortality, and discounted cost/life-year gained for screening by fecal DNA testing (F-DNA), fecal occult blood testing (FOBT) and/or sigmoidoscopy, or colonoscopy (COLO) in persons at average CRC risk from age 50 to 80 years.Compared with no screening, F-DNA at a screening interval of 5 years decreased CRC incidence by 35% and CRC mortality by 54% and gained 4560 life-years per 100,000 persons at USD $47,700/life-year gained in the base case. However, F-DNA gained fewer life-years and was more costly than conventional screening. The average number of colonoscopies per person was 3.8 with COLO and 0.8 with F-DNA. In most 1-way sensitivity analyses and Monte Carlo simulation iterations, F-DNA remained reasonably cost-effective compared with no screening, but COLO and FOBT dominated F-DNA. Assuming fecal DNA testing sensitivities of 65% for CRC and 40% for large polyp, and 95% specificity, a screening interval of 2 years and a test cost of USD $195 would be required to make F-DNA comparable with COLO.Fecal DNA testing every 5 years appears effective and cost-effective compared with no screening, but inferior to other strategies such as FOBT and COLO. Fecal DNA testing could decrease the national CRC burden if it could improve adherence with screening, particularly where the capacity to perform screening colonoscopy is limited.

Abstract

Colorectal cancer is the second leading cause of cancer-related death in the Western world. Screening for colorectal neoplasia, including the removal of adenomas, is highly effective and cost-effective in reducing colorectal cancer incidence and mortality. However, only a minority of the population is currently screened. Based on data from animal models, observational studies and randomized trials in humans, nonsteroidal anti-inflammatory drugs appear to have great promise as chemopreventive agents against colorectal cancer. The critical factors that will determine the roles of aspirin, other nonselective nonsteroidal anti-inflammatory drugs and selective cyclooxygenase-2 inhibitors in colorectal cancer chemoprevention include the magnitude of their protective effect, their risks, their costs, the treated population's characteristics, treatment adherence rates and how chemoprevention compares with established screening strategies.

Abstract

Streptococcus pneumoniae-associated infections are an important cause of hospitalization and mortality in high-risk and elderly patients. Even in the setting of appropriate therapy, the case fatality rate of invasive pneumococcal disease in the elderly may approach 40%. Since approximately 40,000 people die annually from pneumococcal-associated disease, it represents a substantial target for vaccine-preventable, bacterial fatalities. The 23-valent pneumococcal polysaccharide vaccine has proven consistently effective in preventing invasive pneumococcal disease. Despite its endorsement by numerous specialty societies, the pneumococcal vaccine is underutilized in the inpatient setting. In a recent report of quality indicators for Medicare beneficiaries, the percentage of Medicare beneficiaries in Louisiana admitted with pneumonia who were screened or received the pneumococcal vaccination prior to discharge was only 4%, the lowest percentage in the United States. The Louisiana State University-New Orleans Internal Medicine Department and its house staff embarked upon a retrospective study to determine its baseline pneumococcal vaccination or screening rates for all patients with pneumonia on its inpatient services at the The Medical Center of Louisiana in New Orleans from July 2000 through June 2001. From July 2001 through June 2002 an intensive educational intervention concentrating on the indications and benefits of pneumococcal vaccination was directed toward the Louisiana State University Internal Medicine house staff assigned to the inpatient service. Retrospective analysis for pneumococcal vaccine screening and administration of charts of all patients with pneumonia on the LSU Medicine service from July 2001 through June 2002 was performed in order to determine the effects of the intervention. Data from the pre-educational intervention period revealed a baseline pneumococcal vaccine screening or administration rate of 11% for all patients with pneumonia on the LSU Internal Medicine inpatient service. During the one-year intervention period, the pneumococcal vaccine screening or administration rate increased to 71%, a clinically and statistically significant increase (p-value < 0.0001). Data targeting patients 65 years of age and older revealed a baseline pneumococcal vaccine screening or administration rate of 10% for patients with pneumonia on the LSU Internal Medicine inpatient service which increased to 82% during the one year educational intervention (p-value < 0.0001). House officer scores (possible range 0-100) on a questionnaire assessing their understanding of the indications and benefits of pneumococcal vaccination were significantly higher after the educational intervention compared to before the intervention (means +/- standard deviations, 68 +/- 9 vs. 59 +/- 10, p < 0.0001). The findings from this study highlight the importance of education in increasing compliance with widely-accepted practice guidelines such as pneumococcal vaccine screening or administration in patients hospitalized with pneumonia.

Abstract

To estimate the potential cost-effectiveness of colorectal cancer chemoprevention with cyclooxygenase-2-specific inhibitors (COX-2 inhibitors).Using a decision analytic Markov model, we estimated the discounted cost per life-year saved for three strategies: a COX-2 inhibitor alone; as an adjunct to colonoscopy every 10 years in persons at average risk of colorectal cancer; and as an adjunct to colonoscopy every 5 years in persons with first-degree relatives who had colorectal cancer.In the base case, the incremental cost per life-year saved with a COX-2 inhibitor alone compared with no screening was 233,300 dollars in persons at average risk of colorectal cancer and 56,700 dollars in persons with 2 first-degree relatives who had the disease. Chemoprevention was both less effective and more costly than screening. The incremental cost per life-year saved with a COX-2 inhibitor as an adjunct to screening was 823,800 dollars in persons at average risk and 404,700 dollars in persons with 2 first-degree relatives who had colorectal cancer. Combining a COX-2 inhibitor with less frequent screening was not as cost-effective as screening at currently recommended intervals. Cost-effectiveness estimates were highly sensitive to the cost of COX-2 inhibitors and their effect on the risk of cancer.Chemoprevention of colorectal cancer with COX-2 inhibitors is likely to incur substantially higher costs per life-year saved than are currently recommended screening strategies. COX-2 inhibitor use as an adjunct to screening may increase life expectancy, although at prohibitive costs, and is unlikely to result in less frequent screening.

Abstract

Functional gastrointestinal disorders cause substantial morbidity, but not mortality. Alosetron may achieve 'adequate relief ' in diarrhoea-predominant irritable bowel syndrome, but may cause major complications, including death.To appraise, quantitatively, the trade-off between possible symptomatic improvement and serious complications in the treatment of functional gastrointestinal disorders.A decision analytical model was used to examine alosetron or standard treatment for 6 months in 45-year-old women with diarrhoea-predominant irritable bowel syndrome using the health care system's perspective.Assuming a 14% higher 'adequate relief' rate with alosetron compared to standard care, and a complication rate of four per 1000 persons in 6 months, alosetron gained 0.00081 quality-adjusted life-years (QALYs) per patient at a cost of 358,700 US dollars per QALY gained. Alosetron gained QALYs if 'adequate relief' increased the patients' utility by more than 0.01 in the base case. In probabilistic analysis, alosetron gained QALYs in 98.2% of iterations at a median cost of 212,600 US dollars per QALY (interquartile range, 138,000-338,900 US dollars per QALY). Results were highly sensitive to the utility gain with 'adequate relief' and alosetron's response and complication rates.Alosetron's benefit-to-risk profile appears to be favourable, but its cost per QALY gained may be substantial. Decision analyses on treatments for functional gastrointestinal disorders are likely to be highly sensitive to the utility estimates used. There is a pressing need for direct utility measurements in functional gastrointestinal disorders.

The yield of lower endoscopy in patients with constipation: survey of a university hospital, a public county hospital, and a Veterans Administration medical centerGASTROINTESTINAL ENDOSCOPYPepin, C., Ladabaum, U.2002; 56 (3): 325-332

Abstract

The role of endoscopy in the evaluation of constipation is controversial. The aim of this study was to clarify the yield of lower endoscopy in patients with constipation.Endoscopic databases from 3 diverse hospitals were searched for procedures with constipation as an indication. Detection of neoplasia was the main outcome of interest.Among 19,764 sigmoidoscopies or colonoscopies, constipation was a procedure indication for 563 patients (mean age 61 [16] years, 52% women); 58% had procedure indications in addition to constipation. Colorectal cancer was diagnosed in 8 (1.4%), adenomas in 82 (14.6%), and advanced lesions (cancer or adenoma with malignancy, high-grade dysplasia, villous features, or size > or = 10 mm) in 24 (4.3%). In the 358 patients who underwent colonoscopy, cancer was detected in 1.7%, adenomas in 19.6%, and advanced lesions in 5.9%. Two patients with cancer were less than 50 years of age. In as many as 6 patients with cancer, the tumor may have caused partial obstruction.The range of neoplasia in patients with constipation evaluated with lower endoscopy was comparable with what would be expected in asymptomatic subjects undergoing colorectal cancer screening. Although chronic constipation alone may not be an appropriate indication for lower endoscopy, age-appropriate colorectal cancer screening should be pursued when patients with constipation seek medical care.

Abstract

The benefits of the Helicobacter pylori test-and-treat strategy are attributable largely to the cure of peptic ulcer disease while limiting the use of endoscopy.To reappraise the test-and-treat strategy and empirical proton pump inhibitor therapy for the management of uninvestigated dyspepsia in the light of the decreasing prevalence of H. pylori infection, peptic ulcer disease and peptic ulcer disease attributable to H. pylori.Using a decision analytical model, we estimated the cost per patient with uninvestigated dyspepsia managed with the test-and-treat strategy ($25/test; H.pylori treatment, $200) or proton pump inhibitor ($90/month). Endoscopy ($550) guided therapy for persistent or recurrent symptoms.In the base case (25%H. pylori prevalence, 20% likelihood of peptic ulcer disease, 75% of ulcers due to H.pylori), the cost per patient is $545 with the test-and-treat strategy and $529 with proton pump inhibitor, and both strategies yield similar clinical outcomes at 1 year. H. pylori prevalence, the likelihood of peptic ulcer disease and the proportion of ulcers due to H.pylori are important determinants of the least costly strategy. At an H. pylori prevalence below 20%, proton pump inhibitor is consistently less costly than the test-and-treat strategy.As the H. pylori prevalence, the likelihood of peptic ulcer disease and the proportion of ulcers due to H. pylori decrease, empirical proton pump inhibitor becomes less costly than the test-and-treat strategy for the management of uninvestigated dyspepsia. Given the modest cost differential between the strategies, the test-and-treat strategy may be favoured if patients without peptic ulcer disease derive long-term benefit from H.pylori eradication.

Abstract

Dyspepsia, which is defined as pain or discomfort centered in the upper abdomen, is encountered frequently in primary care and subspecialty practice. Dyspepsia is a symptom complex caused by a heterogeneous group of disorders and diseases. A large fraction of patients with dyspepsia suffer from functional dyspepsia, in which no evidence of organic disease (typically on the basis of upper endoscopy) is found to explain persistent or recurrent symptoms. Initial management strategies for uninvestigated dyspepsia include empiric antisecretory therapy, the "test-and-treat" strategy for Helicobacter pylori, or prompt upper endoscopy. The cost-effectiveness of empiric therapy versus the test-and-treat strategy is dependent upon a number of variables including the prevalence of H. pylori infection, ulcer prevalence, and likelihood that an ulcer is due to H. pylori infection. As the prevalence of H. pylori infection falls and the likelihood of H. pylori negative ulcer increases, empiric antisecretory therapy will become more cost-effective. Upper endoscopy should be reserved for patients older than 45 to 50 years with symptom presentation and those with warning signs. Endoscopy also should be considered in those for whom empiric therapy or an attempt at the test-and-treat strategy fails. Common-sense dietary counseling can be helpful in patients with meal-related symptoms. Highly restrictive diets rarely improve symptoms and may be counterproductive if nutrition is compromised.

Abstract

Aspirin may decrease colorectal cancer incidence, but its role as an adjunct to or substitute for screening has not been evaluated.To examine the potential cost-effectiveness of aspirin chemoprophylaxis in relation to screening.Markov model.Literature on colorectal cancer epidemiology, screening, costs, and aspirin chemoprevention (1980-1999).General U.S. population.50 to 80 years of age.Third-party payer.Aspirin therapy in patients screened with sigmoidoscopy every 5 years and fecal occult blood testing every year (FS/FOBT) or colonoscopy every 10 years (COLO).Discounted cost per life-year gained.When a 30% reduction in colorectal cancer risk was assumed, aspirin increased costs and decreased life-years because of related complications as an adjunct to FS/FOBT and cost $149 161 per life-year gained as an adjunct to COLO. In patients already taking aspirin, screening with FS/FOBT or COLO cost less than $31 000 per life-year gained.Cost-effectiveness estimates depended highly on the magnitude of colorectal cancer risk reduction with aspirin, aspirin-related complication rates, and the screening adherence rate in the population. However, when the model's inputs were varied over wide ranges, aspirin chemoprophylaxis remained generally non-cost-effective for patients who adhere to screening.In patients undergoing colorectal cancer screening, aspirin use should not be based on potential chemoprevention. Aspirin chemoprophylaxis alone cannot be considered a substitute for colorectal cancer screening. Public policy should focus on improving screening adherence, even in patients who are already taking aspirin.

Abstract

Somatic and visceral sensation, including pain perception, can be studied noninvasively in humans with functional brain imaging techniques. Positron emission tomography and functional magnetic resonance imaging have identified a series of cerebral regions involved in the processing of somatic pain, including the anterior cingulate, insular, prefrontal, inferior parietal, primary and secondary somatosensory, and primary motor and premotor cortices, the thalamus, hypothalamus, brain stem, and cerebellum. Experimental evidence supports possible specific roles for individual structures in processing the various dimensions of pain, such as encoding of affect in the anterior cingulate cortex. Visceral sensation has been examined in the setting of myocardial ischemia, distension of hollow viscera, and esophageal acidification. Although knowledge regarding somatic sensation is more extensive than the information available for visceral sensation, important similarities have emerged between cerebral representations of somatic and visceral pain.

Abstract

Motility of the small intestine is controlled by myogenic, neural, and hormonal mechanisms and is modulated by external influences such as meals, central nervous system activation, and immune factors. Small-bowel dysmotility is recognized in a number of diseases, but its precise role in symptom generation remains unclear in many instances. We review publications that in the year under review added to the basic understanding of small-intestinal motility as well as its alteration in disease.

Abstract

Nausea and vomiting are debilitating symptoms complicating many clinical conditions. Conventional antiemetic agents act as muscarinic, histamine, and dopamine receptor antagonists in the central nervous system. In a retrospective analysis, tricyclic antidepressant drugs demonstrated efficacy in long-term treatment of functional nausea. Some cases of vomiting result from impaired gastrointestinal motor activity. Agents which act on gastric serotonin (5-HT4), dopamine, and motilin receptors accelerate gastric emptying and relieve symptoms in gastroparesis. Recent investigations suggest that some patients with refractory gastroparesis may benefit from gastric electrical pacing. The treatment of acute chemotherapy-induced emesis was revolutionized by 5-HT3 receptor antagonists; however, these agents are less efficacious in delayed vomiting. Neurokinin (NK-1) receptor antagonists show promise in treating delayed chemotherapy-evoked emesis. Furthermore, animal studies indicate a broad spectrum of action for NK-1 antagonists in treating diverse causes of nausea and vomiting. The cyclic vomiting syndrome is characterized by discrete episodes of relentless vomiting separated by asymptomatic intervals and is associated with migraine headaches. Antimigraine therapies including the 5-HT1D receptor agonists sumatriptan reduce the severity of cyclic vomiting attacks. Investigations into these and other novel treatments may provide important advances in the care of difficult cases of nausea and vomiting resulting from disparate illnesses.

Abstract

Colonic motor function is modulated by extended and local neural reflexes involving unknown mediators. To test the role of serotonin (5-HT3) pathways, increases in colonic tone during antral distension and duodenal lipid perfusion (gastrocolonic responses) and changes in orad and caudad colonic tone in response to local colonic distension (peristaltic reflex) were measured after double-blind granisetron (10 microg/kg) or placebo infusion in healthy human volunteers. Antral distension evoked increases in colonic tone, which were blunted by granisetron (P < 0.05) without effects on antral compliance. Intraduodenal lipid perfusion also evoked increased colonic tone, which was reduced by granisetron (P < 0.05). In contrast, orad colonic contractions and caudad relaxations and contractions during colonic distension were unaffected by granisetron. In conclusion, 5-HT3 receptor antagonism blunts both the mechano- and chemoreceptor components of the human gastrocolonic response without altering antral compliance. In contrast, 5-HT3 pathways play no role in the ascending or descending components of the colonic peristaltic reflex. These findings demonstrate different roles for 5-HT3 receptors in the control of colonic motor function by the proximal gastrointestinal tract and by local neural reflexes.

Abstract

Nausea and gastric dysrhythmias occur in conditions associated with gastric distension. The roles of distal and proximal gastric mechanoreceptors in these responses are unexplored. Because antral distension induces vomiting in animals and antral and fundic vagal afferent discharges differ, we hypothesized that distal gastric distension in humans leads to greater symptomatic and dysrhythmic responses than proximal distension. Symptoms and electrogastrograms were recorded in healthy humans during distal and proximal gastric distension with a barostat. Distal but not proximal distension induced nausea and a 747 +/- 250% increase in dysrhythmic power (P < 0.05), responses not affected by granisetron, indomethacin, or atropine, agents that block dysrhythmias in other settings. In the distal stomach, bloating and pain developed at lower pressures (P < 0.05) not modified by granisetron, and compliance was significantly lower (P < 0.05). In conclusion, gastric mechanoreceptor activation in the less-compliant distal stomach produces nausea and dysrhythmias via non-5-hydroxytryptamine3 (5-HT3), non-prostaglandin-dependent, and noncholinergic pathways. Distal mechanoreceptor activation induces greater bloating and pain than proximal mechanoreceptor activation via 5-HT3-independent pathways.